1. Field of the Invention
The present invention pertains generally to surgical instruments and, more particularly, to surgical instruments such as an acetabular cup impactor particularly suited for use in minimal invasive surgical procedures.
2. Description of the Related Art
Early techniques for performing major orthopedic surgical procedures, such as joint replacements or reconstructions, included making large incisions and exposing the entire joint. Even with a successful surgery, the trauma to the patient is significant from open surgical procedures. As a result, rehabilitation periods are long and require dedication from the patient over an extended difficult time period to ensure the best possible result. Even with a skilled surgeon and a patient committed to a rehabilitation program, it is not always possible to achieve the desired results due in part to the surgical damage to areas surrounding the joint and the extensive scaring that can result.
In an effort to reduce trauma caused by open surgical procedures, it is desirable to reduce the size of incisions. Some procedures, such as many procedures performed on knees, now are routinely performed arthroscopically. Small incisions are made at discrete locations around the knee, and surgical tools are inserted through the incisions for performing the required procedures. Inspection of the joint, and observation of the procedure are achieved remotely, using fiber optics inserted through one of the incisions to illuminate the site and display a picture thereof on a view screen.
Procedures for knees and some other joints are readily adaptable to arthroscopic performance, using essentially straight, inline surgical tools. However, procedures for some other joints, such as hips, are not as easily adapted to minimally invasive surgical procedures. Because of surrounding hard and soft tissue structures, it is difficult to position properly inline surgical tools through incisions spaced about the joint. For example, to set an acetabular cup in a properly prepared acetabulum, an acetabular cup impactor is used. An surgical implement coupler of the impactor is secured to the acetabular cup. An elongated shaft is joined to the surgical implement coupler at one end, and includes a striker cap at the opposite end of the shaft. The cup is seated in the prepared acetabulum by positioning the cup in the prepared depression, and imparting a series of blows from a mallet against the striker cap. The force of the blows is transmitted through the shaft of the impactor, to seat the cup in the prepared opening in the acetabulum. After the cup is properly seated, the surgical implement coupler of the impactor is detached from the cup.
Two problems occur in seating an acetabular cup in this manner during a minimally invasive procedure. It is difficult to properly align the impactor because of anatomical features that are in the way, and disconnecting the head from the cup is more difficult with limited access to the end of the tool.
As a consequence, many common hip procedures, such as total hip replacements, are routinely performed through large incisions, in open procedures, exposing the entire joint, with the increased trauma caused thereby perceived as a necessary disadvantage.
What is needed in the art is an acetabular cup impactor that is more easily used during minimally invasive procedures.